Ruler is a pattern constructed by Dean Hickerson in April 2005 that produces a stream of LWSSes with gaps in it, such that the number of spaceships between successive gaps follows the "ruler function" (sequence A001511 in The On-Line Encyclopedia of Integer Sequences).
The first length-n series of LWSSes is emitted at approximately generation 96*2^n. The pattern uses a Corderman eaterpuffer found by Paul Tooke in January 2004, a p48 glider gun by Noam Elkies in June 1997, a p8 bouncer by Noam Elkies in September 1998, and a p24 LWSS puffer (source unknown).
